Human beings all belong to the species Homo sapiens. However, both Neanderthals and modern humans are most likely the homo heidelbergensis descendants. Homo sapiens are believed to have evolved in Africa nearly 200,000 years ago and gradually migrated north, through the Middle East, to Europe and Asia. A skull 160,000 years old was discovered at the Herto site area of Ethiopia (Anthro.palomar.edu, 2010). Other more advanced transitional forms have been discovered at Laetoli in Tanzania and are 120,000 years old. About 115,000 years ago, some early modern humans (Homo sapiens) ago widened their range to South Africa as well as Southwest Asia, a few years after 100,000 years ago (Bradley & Stanford, 2004). According to Anthro.palomar.edu (2010), there is no reliable evidence to suggest that there were modern humans anywhere else in the Old World before 60,000 years ago.
It is believed that different groups of hominids lived in different parts of the world, nearly 100,000 years ago. The main regions were Africa and the Middle East where Homo sapiens occupied; Asia, which was occupied by the Homo erectus; and in Europe where the Homo neanderthalensis lived. However, around 30,000 years ago, all the groups of hominids evolved into the modern human form (Anthro.palomar.edu, 2010). This human transformation has been debated by two different schools of thought: one group proposes multiregional continuity thought, and the other school supports the single origin for modern humans believed to be Africa (Bradley & Stanford, 2004). The multiregional view argues that after the first hominid, Homo erectus dispersed from Africa to different regions of the world, with time, they evolved slowly into the modern human form (Tattersall, 2009). After Homo erectus dispersed from their land of origin, some level of gene flow between geographically separated populations prevented new distinct species formation. The regional variances present in occupants (races) are as a result of natural selection. In contrast, the single origin theory argues that all humans’ origin is Africa. Out of Africa Model argues that modern humans evolved in Africa and migrated to other parts of the world, replacing other hominids.
Many of the distinctive features of Homo sapiens are found in the skull. The brain of Homo sapiens was larger than that of other hominin species (Tattersall, 2009). The average cranial capacity of Homo sapiens is roughly 1300 cubic centimeters, making the brains of this species smaller than those of Homo neanderthalensis (Tattersall, 2009). However, due to its small and lightly built postcranial skeleton (see below), the brain of H. sapiens was larger about body size than that of H. neanderthalensis
There are various theories used to explain the disappearance of the Neanderthals and Homo erectus. For example, according to some scientists, a volcanic eruption could have wiped out the entire Neanderthal population (Tattersall, 2009). The Campi Flegrei, located to the west of Naples, erupted devastatingly 39,000 years ago, the resulting poisonous smoke plumes and ash may have had a catastrophic impact on the Neanderthals. Other theorists have indicated that harsh climate is responsible for the elimination of the Neanderthal and Homo erectus species. The Neanderthals did not have the technology to make protective clothing or the social and cognitive know-how for them to form social interactions that would have enabled them to survive.
Homo sapiens was able to spread to many different parts of the world because of various strategies and abilities. Socially, individuals from the species could communicate and heavy social relations with one another. This ability enabled them to coordinate migratory movements and survive predators. Also, the species had a comparatively developed brain that assisted in coordinating activities such as hunting and gathering that brought food. The species could also outwit dangerous prey in their travels. Homo sapiens also wore animal skins to keep warm and could, therefore, survive in different climates.
Today, modern humans use the social construct of race to differentiate themselves. There is no scientific foundation for the application of the race concept to human variation. Humans are also differentiated from their earlier ancestors by their lack of significant body hair and bipedalism (Bradley & Stanford, 2004). Males are larger than females and have greater muscle development. Males also have more facial hair than females.
Homo sapiens started to organize permanent structures and settlements almost 10,000 years ago in the area known as the Fertile Crescent between the Tigress and Euphrates rivers. This area is the modern day Iraq. Homo sapiens had started to use simple digging tools. These new technologies enabled the Homo sapiens populations to till the land and plant crops. Agriculture offered Homo sapiens an easier time to get food. Also, it allowed them to settle in one place even when there were fewer animals to hunt (Bradley & Stanford, 2004). Agriculture enabled the populations to increase in number. One of the drawbacks of agriculture is that it slowed down the discovery of new places and new things because the rate of migration decreased considerably.
References
Anthro.palomar.edu, (2010). Basic Principles of Genetics: Mendel's Genetics.Anthro.palomar.edu. Retrieved 30 May 2016, from http://anthro.palomar.edu/mendel/mendel_1.htm
Bradley, B. & Stanford, D. (2004). The North Atlantic ice-edge corridor: A possible Palaeolithic route to the New World. World Archaeology, 36(4), 459-478. http://dx.doi.org/10.1080/0043824042000303656
Tattersall, I. (2009). Human origins: Out of Africa. Proceedings of The National Academy of Sciences, 106(38), 16018-16021. http://dx.doi.org/10.1073/pnas.0903207106
